The latest trend in HDTVs, other than 3-D, is for Internet connectivity. This started as mundane weather and news items, little more than snippets of the Web. Now, with the release of Google TV, (nearly) full Internet surfing from your TV is possible. In between are numerous content providers, all with different content and quality, and all looking for your entertainment dollar.

The first thing you'll need, of course, is an Internet connection. For high-definition content, most providers require at least a 2.5-megabit-per-second (Mbps) connection. For some, like Vudu, the top tier 1080p HD stream requires 4.5 Mbps.

If your connection isn't this fast, you may be relegated to only watching standard definition streams, or a feed that's automatically bumped to a lower quality by the video provider. Connecting wired or wirelessly from your router doesn't generally matter, as most Wi-Fi signals can handle even HD streams. If you have difficulties with a service, and you know it's not your Internet provider who's at fault, switching from Wi-Fi to to wired Ethernet is worth a try, but that might be difficult if your TV isn't near a router.

Video and audio content comes in two basic flavors: subscription and pay per view. Providers are somewhat cagey about how many shows/films they provide, and how many are in HD.

For example, Vudu claims the highest number of HD movies with "over 3,000," while CinemaNow claims over 14,000 total movies, but with no indication of how many are in HD. In truth, when it comes to pay-per-view movie download services like these, each content provider inventories most of the available content that you may be looking for. It's really Hollywood that controls what's available, and when a movie is released for paid viewing on-demand, most services can offer it. (The all-you-can-eat monthly subscription services are quite different, as you'll see.)

Here's the breakdown of the different services offered. To learn the more about the TV makers that supply each service (LG, Mitsubishi, Panasonic, Philips, Samsung, Sharp, Sony, Toshiba and Vizio) check out the graph below.

Please note: Not all of the models within a manufacturers line may provide all the listed services. Consult the manufacturer's website or dealer to confirm that the TV you are considering offers the services you desire before purchase. You usually have to go up a notch or two from the lowest price points.

Netflix - The near-universal adoption of Netflix's streaming service in TVs (and also Blu-ray players) is a testament to the quality of the content you can get. Not picture quality, mind you, which is predominantly standard definition and only occasionally 720p HD. The content quality, in terms of finding something worth watching, is excellent. Most people will be able to find something to watch any time they chose to.

Not all content is available for streaming, and most of Netflix's streaming content is usually a year or so old or older. But catching up on TV shows from a few years ago, or newer documentaries and indie films, not to mention thousands of Hollywood movies, all make this service well worth the small monthly cost.

What's the cost? The cheapest plan as of this writing is a $8.99 a month which includes unlimited streaming, plus one DVD disc at a time mailed to your house. There is talk of a slightly cheaper plan ($7.99, some say) that will be streaming only, with no DVD mailing.

Picture quality-wise, even the best HD content isn't quite as pristine as what you get on most cable or satellite providers. That said, it's not bad. I watch Netflix on a 100-inch projection screen, and I have never had an issue. Sure Blu-ray looks better, but you're trading for convenience. Videos are streamed using the VC1 Advanced Profile codec with 2.0 stereo audio.

The PlayStation 3 is the first, and so far only, device to get 5.1 Dolby Digital Plus surround sound and 1080p content streaming from Netflix. There's no word if this will come to current or future TVs with built-in Netflix.

Netflix is so cheap, so convenient, and offers so much entertainment, it's the proverbial no-brainer. Do you need to buy it pre-loaded in your TV though? Not if you have it in your Blu-ray player, PS3, Xbox 360, Apple TV or another compatible source device. If you don't, I can honestly say it's well worth looking at a TV with it. Thankfully, nearly every major TV company offers it.

YouTube - Calling YouTube entertainment stretches my definition. Watching 30-second clips of narcoleptic dogs (seriously, Google it) is one thing, but I just can't picture people sitting around a TV for hours searching for things using the TV's alphanumeric remote.

The biggest reason for this is picture quality. Watching a clip in a tiny window in your Internet browser is one thing. Watching it on a 50-inch flat panel is entirely another. No matter what you do, or what fancy processing your TV has, most YouTube clips are going to look horrible. As in, barely watchable.

So don't expect much. Still, for what little it's worth, most connected TVs have YouTube as an option.

Amazon Video on Demand - AVoD is a pay-per-view streaming service by, wait for it ... Amazon. Current movies and TV episodes (including the most recent episodes) are available. Prices for rentals are 99 cents to $1.29 for TV shows, and $1.99 to $3.99 for movies. For purchase, prices are $5.99 to $19.99, though most are $14.99 to $15.99.

Picture quality is perhaps a little better than Netflix, though that's going to vary depending on what you choose to watch. HD is compressed with VC-1 codec and 720p. The big advantage is being able to watch current TV shows and movies whenever you want. Not quite the excellent deal that Netflix is, but extremely convenient none the less, especially if you want to watch the most recent movies and TV episodes.

Vudu - Unlike Netflix and Amazon, Vudu has 1080p and uses the H.264 codec similar to many Blu-ray discs. Audio output is 5.1 Dolby Digital Plus.

There are three picture quality levels to Vudu's downloads: SD, HD, and HDX. SD is 480p, and only requires a 1 mbps Internet speed. HD is 720p, and requires 2.5 mbps. The top-of-the-line HDX is 1080p and needs 4.5 mbps. Great picture quality with its HDX titles is how Vudu tries to differentiate itself, and if that's of importance to you as well, then the additional money to rent from Vudu will be less of a concern.

Movie rentals range in price from 99 cents to $5.99, but the lower prices aren't for HD. For the highest-quality HDX files, expect to pay on the higher end of the scale. You can also buy movies, but these range up to $24.99 for HDX, and for that rate we're not sure why you wouldn't just buy a Blu-ray. Vudu is owned by Wal-Mart, though as of yet no greeters are planned to welcome you to your downloaded content.

Vudu is certainly great for those who want the best picture quality, as either a 24-hour window or stored on their server indefinitely but who are too lazy to drive to a Best Buy and get the disc.

Hulu Plus - Hulu.com is a fantastic, free way to watch new shows from the ABC, NBC and Fox networks, and their various sister channels and studios. The "Plus" in Hulu Plus is plus money, yours, to the tune of $7.99 a month, as announced Nov. 17.

For the monthly fee you get to watch Hulu content on your TV, with the same commercials as the free computer-only Web version. You also get access to entire seasons and a larger back catalog. Streaming resolutions up to 720p are available, but don't expect much from picture quality.

Most consider Hulu Plus like a crappy version of Netflix with more up-to-date content. If you want to get rid of your cable bill, but can't wait for the content to be available on Netflix, then Hulu Plus has merit. Only a few TVs have this built in, as it's quite new.

CinemaNow - CinemaNow has 1080p downloads much like Vudu using primarily the VC-1 codec. Rental prices range from $2.99 and $3.99 and purchase prices range from $9.95 to $19.99. Though branded by Best Buy (even cross-promoting their Napster music service), CinemaNow is owned primarily by Sonic Solutions. And remember, they don't reveal how much of their "extensive library" is available in HD.

Blockbuster on Demand - Having recently announced bankruptcy, and currently only available from two TV manufacturers, Blockbuster is kind of an also-ran. They, like Best Buy, have partnered with CinemaNow. But unlike Best Buy, there is little to no mention of HD on Blockbuster's site. Rentals seem to range from $1.99 to $3.99, with purchases around $17.99. There is very little information about Blockbuster on Demand on their website or elsewhere, which is sketchy, in my book. Unlikely they'll survive long, at least in their current state, so this may all be moot.

Music
Pandora and Slacker - Pandora and Slacker are free music streaming services. Internet radio, if you like. In theory, they're competitors, but in usage they're very similar. They both let you pick an artist or song, and then their algorithms play music similar to that artist or song. It works great and is free, with just a few advertisements.

Both offer a subscription service that is higher quality, fewer (if any) ads, and a few advanced features. Both are great and if you haven't checked them out, you should. If there's no other way to get music into the room where your TV is, and your TV speakers don't suck too bad (sorry, they do), then these are a great thing to have. Sound quality is roughly on par with your average MP3 download. This is to say it's passable, but a far cry from CD despite "CD quality" claims by each.

Napster - The pay service called Napster (now owned by Best Buy), has nothing to do with this brand's storied past. For $5 to $10 a month you can stream unlimited amounts of music. The difference between Napster and Pandora/Slacker is that you can choose what you want to play. Pandora and Slacker are more like a radio station, playing random songs that fit the style of music you choose.

Rhapsody - Rhapsody is a subscription music service. For $10 to $15 a month you can download all the music you want and listen to it as much as you want. It's a lease, though, as once you stop paying for the service, you can no longer play any of the songs you downloaded.

The rest
Twitter and Facebook need little introduction. Though why you would need them on a TV is beyond me.

Skype is a program that allows you to make free voice and video calls over the Internet. You'll need a video camera add-on for this and they are all manufacturer-specific, meaning brand X video camera will only work with brand X TV. Currently, only Samsung and Panasonic offer Skype video service, although more companies are expected to join next year. For more on Skype video, check out our review here.

Flickr and Picasa are Web services to share photos. Upload from your computer, share them in the living room.

Lastly, Sony is currently making a line of TVs that have Google TV built in. So far Google TV is underwhelming, offering similar content streaming capabilities as other TVs, just adding in a Web browser for full Internet surfing, something no other TV offers. Be aware, most major networks have blocked programming on their respective websites from Google TV. It is assumed they're holding out for a piece of Google's revenue. Whether this situation continues or expands to other websites remains to be seen.

Conclusion
It's unlikely that any one service will fill all your needs. The subscription services, Netflix and Hulu Plus, don't offer the variety that the pay-per-view services (Amazon Video on Demand, Vudu, CinemaNow and Blockbuster) provide, but none of the pay-per-view services will likely have everything you're looking for either. For most people, Netflix plus Vudu or Amazon will offer the best compromise between price and selection. Add in Hulu Plus and most of your needs will be met.

Most connected TVs include a lot of other channels not mentioned here, mostly curated Web video. I'd classify them as a bit of faff, but to each their own.

Please keep in mind that companies are changing what services they offer practically on a daily basis. So if company X starts offering Twitter or some service, don't fret. The big stuff is covered here, and correct as of press time.